1. Field of the Invention
The present invention relates to a matrix switch. Particularly, the present invention relates to a matrix switch having a plurality of inputs and a plurality of outputs.
2. Description of Related
A matrix switch (switch matrix) is a circuit for internally connecting a plurality of input-terminals and a plurality of output-terminals. The connection is controlled in response to electric signals input to control terminals. A technique relevant to the matrix switch is described in the following patent document.
Japanese Laid Open Patent Application JP-P2005-311688A discloses a switch matrix. The switch matrix disclosed in Japanese Laid Open Patent Application JP-P2005-311688A is provided with two input-terminals, two input-side SPDT (Single-Pole Double-Throw) switches, four transmission lines, two output-terminals, and two output-side SPDT switches. Each of the input-side SPDT switches and the output-side SPDT switches includes two field-effect transistors as constituent elements. In the each SPDT switch, drains or sources of the two field-effect transistors are connected to one common terminal, while the others of the drains and the sources are respectively connected to two switch terminals. The two input-terminals are connected to the common terminals in the two input-side SPDT switches, respectively. The two output-terminals are connected to the common terminals in the two output-side SPDT switches, respectively. Moreover, the two switch terminals in the input-side SPDT switches and the two switch terminals in the output-side SPDT switches are connected one-to-one by the respective four transmission lines, such that a signal can be transmitted from each of the input-side SPDT switches to each of the output-side SPDT switches. Furthermore, the two switch terminals in each of the input-side SPDT switches are connected to each other through a resistor, or the two switch terminals in each of the output-side SPDT switches are connected to each other through a resistor.